(.9) United States
`(12) Patent Application Publication (10) Pub. No.: US 2008/0018816 A1
`HATTORI et al.
`(43) Pub. Date:
`Jan. 24, 2008
`
`US 20080018816A1
`
`(54) LIQUID DISPLAY DEVICE AND
`
`Publication Classification
`
`(76)
`
`FABRICATION METHOD THEREOF
`Inventors:
`Takashi IIATTORI.
`IvIusashinutmyama (JP); Daisuke
`SON()I)A. (‘hiba (JP): Daisuke
`RYUZAKI. Hitachi (.ll’):
`Kazuvoshi TORII.
`Iligashimumyama (JP)
`
`Correspondencc Address:
`MILES 8: S'l'()(.‘KllRll)GlC P(.'
`175] PINNACLE DRIVE. SUITE 500
`M(?I.EAN. VA 22l02-3833
`
`(21) APP‘- NO-i
`
`11/777,853
`
`(22)
`
`Filed:
`
`Jul. 13. 2007
`
`(30)
`
`Foreign Application Priority Data
`
`Jul. I9. 2006
`
`(JP) ................................. 2006-196375
`
`149/39
`.
`.
`
`Int (1
`(51)
`(2006.01)
`(52) glflcf/Bfl
`.
`.. .
`. .
`.........................................................
`(57)
`ABS’I‘K\C’I‘
`.
`.
`.
`.
`.
`.
`.
`A hqutd crystal display improved WIIII the opening ratio and
`increased for the storage capacitance.
`in which a gate
`insulating film. a gate electrode. an interlayer insulating
`film. an image line and a source electrode are stacked in this
`order formed in the layer above an active device fonned to
`a lirst substrate. the interlayer insulating lilm is formed with
`a coatable transparent
`insulating film having. a specific
`dielectric constant of 4.0 or higher at least containing high
`dielectric fine particle or sol-gel. a first through hole is
`formed in the gate insulating film. a second through hole is
`formed to the interlayer insulating film in the inside of the
`first through hole. the source electrode is electrically con-
`nected with the active device by way of the second through
`hole. and the storage capacitance is constituted by the gate
`electrode.
`the image line.
`the source electrode. and the
`interlayer insulating film.
`
`
`
`Page 1 of 22
`
`Tianma Exhibit 1009
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`

`

`Patent Application Publication
`
`Jan. 24, 2008 Sheet 1 of 7
`
`US 2008/0018816 A1
`
`FIG.
`
`1
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`Page 2 of 22
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`

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`Patent Application Publication
`
`Jan. 24, 2008 Sheet 2 of 7
`
`US 2008/0018816 A]
`
`F FIG. 2
`
`C
`
`11B
`108
`
`BM
`
`13B
`
`158
`
`1008
`
`LC
`
`100A
`
`
`ITO1
`1 5A
`20
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`ITO2
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`1 3A
`
`12D
`3 120
`- 123
`12A
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`10A
`11A
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`Page 3 of 22
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`

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`Patent Application Publication
`
`Jan. 24, 2008 Sheet 3 of 7
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`US 2008/0018816 A1
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`
` FIG. 5A
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`1ng
`
`0M6
`
`D
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`5H3
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`1
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`3
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`2
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`4
`
`FIG 50
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`FIG 50
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`133
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`120
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`Page 4 of 22
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`

`

`Patent Application Publication
`
`Jan. 24, 2008 Sheet 4 of 7
`
`US 2008/0018816 A1
`
`FIG. 6
`8H3
`1
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`D
`
`ITOZ
`
`FIG. 68
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`20b
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`
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`COATING
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`13A
`120
`120
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`3
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`2
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`4 C
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`OATING
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`REMOVAL—>
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`Page 5 of 22
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`

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`Patent Application Publication
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`Jan. 24, 2008 Sheet 5 0f 7
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`US 2008/0018816 A1
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`FIG. 7
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`
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`ITO1
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`30
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`'1'— 1m1
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`1a
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`13A
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`Page 6 of 22
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`Page 6 of 22
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`

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`Patent Application Publication
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`Jan. 24, 2008 Sheet 6 of 7
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`US 2008/0018816 A1
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`FIG. 9
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`ITO3
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`ITO1
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`
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`Page 7 of 22
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`

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`Patent Application Publication
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`Jan. 24, 2008 Sheet 7 ol' 7
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`US 2008/0018816 A1
`
`FIG. 11
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`CF
`
`
`ll
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`1008
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`11B
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`108
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`BM
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`138
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`LC
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`100A
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`
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`
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`ITO3
`158
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`15A
`ITO1
`20
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`ITOZ
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`1 3A
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`12D
`12C
`12 128
`12A
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`10A
`11A
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`Page 8 of 22
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`

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`US 2008/0018816 A1
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`Jan. 24, 2008
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`LIQUID DISPLAY DEVICE AND
`FABRICATION METHOD THEREOF
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`CLAIM OF PRIORITY
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`[0001] The present application claims priority from Japa-
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`nese application JP 2006-196375 filed on Jul. 19, 2006, the
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`content of which is hereby incorporated by reference into
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`this application.
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`FIELD OF THE INVENTION
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`[0002] The present invention concerns a liquid crystal
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`display and a fabrication method thereof and, particularly, it
`is suitable to a substrate formed with an active device
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`(typically, thin film transistor) of a liquid crystal display
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`panel constituting a display portion of a liquid crystal
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`display.
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`BACKGROUND OF THE INVENTION
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`[0003] An active matrix type liquid crystal display using
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`active devices typically represented by thin film transistors
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`(TFT) has been popularized generally as various types of
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`displays in View of the feature of reduced thickness and
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`weight and high picture quality. The display system of the
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`liquid crystal display is generally classified into the follow-
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`ing two types. One of them is a system of sandwiching liquid
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`crystals between two substrates constituted each with a
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`transparent electrode, conducting operation by a voltage
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`applicd to thc transparent clcctrodcs and displaying, undcr
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`modification, a light transmitting the transparent electrode
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`and incident to the liquid crystals, and most of products
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`popularized at present adopt this vertical electric field sys-
`tern.
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`[0004] The other of them is a system referred to as a
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`transverse electric field system or an in-plane switching
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`(IPS) system. The IPS system liquid crystal display panel is
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`adapted to generate a electric field which is parallel With a
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`substrate surface in at least a portion thereofbetween a pixel
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`electrode and a counter electrode and display images by
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`driving liquid crystals by the electric field thereby modifying
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`a light transmitting a liquid crystal layer, and it has a feature
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`that a field angle is remarkably Wide. The feature of the
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`active matrix type liquid crystal display adopting the IPS
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`system is described in JP—T No. 5—505247 and JP—T No.
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`6-160878 (Patent Documents 1 and 2).
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`Further, in the IPS system liquid crystal display
`[0005]
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`panel, it has been known a liquid crystal display panel of
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`forming a planar counter electrode and a pixel electrode
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`having a linear portion sandwiching an insulating film,
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`generating an electric field between the planar counter
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`electrode and the pixel electrode having the linear portion,
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`driving the liquid crystal by the electric field and displaying
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`an image by modifying a light transmitting a liquid crystal
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`layer.
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`[0006] Although not particularly relating to the IPS sys-
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`tem, prior art documents concerned with the present inven-
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`tion include JP-A Nos. 5-61057 (Patent Document 3),
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`6-138484 (Patent Document 4), 8-152650 (Patent Document
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`5), 9—90341 (Patent Document 6), 2000—310793 (Patent
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`Document 7), 2001-13518 G’atent Document 8), 2006-
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`18326 (Patent Document 9), 9-127548 (Patent Document
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`10), and 6-242433 (Patent Document 11).
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`[0007]
`Further, as prior art documents concerned with the
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`present invention, 2000-30534 (Patent Document 12), 2003-
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`7135 (Patent Document 13), 2003-2875583 (Patent Docu-
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`ment 14), 2003-288813 (Patent Document 15), and 2004-
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`14297
`(Patent Document
`16) disclose photosensitive
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`material containing high—k dielectric fine particles, although
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`they are not concerned particularly with the IPS system.
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`SUMMARY OF THE INVENTION
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`[0008]
`In the active matrix type liquid crystal display, an
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`opening ratio has been increased for improving high fineness
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`and saving consumption power. The IPS system liquid
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`crystal panel involves a problem in view of the structure
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`thereof that improvement for the opening ratio is difficult
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`compared with the vertical electric field system.
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`In the IPS system liquid crystal display panel using
`[0009]
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`the planar counter electrode described above, a storage
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`capacitance (Cst) is formed with the planar counter elec-
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`trode, the pixel electrode having the linear portion and the
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`insulating film therebetween. The storage capacitance serves
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`to more stably keeping static charges of the pixel electrode.
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`In the IPS system referred to herein, a storage capacitance
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`(Cst) formed so far in a not light transmitting portion is
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`formed in a light
`transmitting portion as a transparent
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`capacitance film. This can improve the opening ratio. In this
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`case, a capacitor of high transparency, having a large capaci-
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`tance and a high Withstand voltage is indispensable.
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`[0010] The capacitance C of a capacitor is represented by
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`the following formula (1)
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`$659941
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`(1)
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`In the formula (1), C: capacitance, 6,: specific
`[0011]
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`dielectric constant, 60: dielectric constant of vacuum, S:
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`electrode area, d: inter-electrode distance.
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`[0012] Accordingly, for obtaining a large capacitance, it is
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`necessary to use a material of high—k dielectric constant,
`increase the electrode area or decrease the inter-electrode
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`distance. For the electrode area, since high fineness is also
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`required, the size is limited. Particularly, in a medium-to-
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`small sized display,
`is indispensable to decrease the
`it
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`electrode area for making it compatible with higher fineness.
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`Then, decrease of the inter-electrode distance is also limited
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`in view of thc problcm for thc control of thc film thickncss
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`or the problem of lowering the withstand voltage.
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`[0013] The present invention has been accomplished for
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`overcoming the problems in the prior art and it intends to
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`provide a capacitor of high transparency, having a high
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`capacitance and having a high Withstand voltage. The fore-
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`going and other objects and novel features of the present
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`invention will become apparent in view of the descriptions
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`of the specification and the appended drawings to be
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`explained hereinafter.
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`[0014] Thc outlinc for thc typical constitution of thc
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`invention is as described below. That is, a liquid crystal
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`display according to the invention includes:
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`(1) a first substrate, a second substrate, and liquid crystals
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`put between the first substrate and the second substrate, in
`which
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`[0015]
`the first substrate includes an active device, a first
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`insulating film disposed to a layer above the active device,
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`a first electrode disposed to a layer above the first insulating
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`film, a second insulating film disposed to a layer above the
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`first electrode, and a second electrode disposed to a layer
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`above the second insulating film,
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`Page 9 of 22
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`Page 9 of 22
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`

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`US 2008/0018816 A1
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`Jan. 24, 2008
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`[0016]
`the second insulating film is a coatable transparent
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`insulating layer having a specific dielectric constant of 4.0 or
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`higher,
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`the first insulating film has a first contact hole,
`[0017]
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`the second insulating film is formed between the
`[0018]
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`first electrode and the second electrode, and in the first
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`contact hole,
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`[0019]
`a second contact hole is formed to the second
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`insulating film in the inside of the first contact hole,
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`the second electrode is a pixel electrode,
`[0020]
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`the second electrode is electrically connected by
`[0021]
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`way of thc sccond contact holc with the activc dcvicc, and
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`a storagc capacitancc is forrncd by tho first clcc-
`[0022]
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`trode, the second electrode, and the second insulating film.
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`(2) Further, in (1) according to the invention, the second
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`clcctrodc can bc a transparcnt clcctrodc.
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`[0023]
`(3) Further, in (l) or (2) according to the invention,
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`the second insulating film can contain at least a transparent
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`film constituting a main material thereof and fine particles
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`having a specific dielectric constant higher than that of the
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`transparent film material.
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`(4) Further, in (3) according to the invention, the grain size
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`of thc finc particlcs having thc spccific diclcctric constant
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`higher than that of the transparent film material can be 30 nm
`or less.
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`(5) Further, in (3) or (4) according to the invention, the fine
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`particles having the specific dielectric constant higher than
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`that of the transparent film material can use the following
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`material (a):
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`[0024]
`titanium oxide, barium titanate, aluminum
`(a)
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`oxide,
`tantalum oxide, zirconium oxide, hafnium oxide,
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`niobium oxide, and yttrium oxide. They may be used each
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`alone or two or more of them may be used in admixture.
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`(6) Further,
`in (l) or (2) according to the invention, the
`
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`second insulating film can be a material at least containing
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`a transparcnt film constituting a main matcrial thcrcof and a
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`sol-gel having a specific dielectric constant higher than that
`
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`of the transparent film material.
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`(7) Furthcr, in (6) according to thc invcntion, thc sol-gcl
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`having a specific dielectric constant higher than that of the
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`transparent film material can use the following material (a)
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`[0025]
`(a)
`titanium oxide, barium titanate, aluminum
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`oxidc,
`tantalum oxidc, zirconium oxidc, hafnium oxidc,
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`niobium oxide, and yttrium oxide. They may be used each
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`alone or two or more of them may be used in admixture.
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`
`(8) Further,
`in any one of (3) to (7) according to the
`
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`
`
`invention, the transparent film constituting the main material
`
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`can contain at least a polymer selected from polyacrylate
`
`
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`
`
`
`
`
`derivatives, polystyrene derivatives, polyolefin derivatives,
`
`
`
`
`and copolymers thereof.
`
`
`
`(9) Further,
`in any one of (3) to (7) according to the
`
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`
`
`invention, the transparent film constituting the main material
`
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`can be a material having photosensitivity.
`
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`
`(10) Further,
`in any one of (l) to (9) according to the
`
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`
`
`invention, the thickness of the second insulating film can be
`100 nm or more and 1000 nm or less.
`
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`in any one of (l) to (10) according to the
`(11) Further,
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`invention, the second insulating film can have a transmit-
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`tance of 90% or more at a wavelength of 450 nm or more and
`800 nm or less.
`
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`(12) Further,
`in any one of (l) to (11) according to the
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`
`invention, the first electrode can be a transparent electrode.
`
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`
`(13) Further, in any one of (l) to (11) according to the
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`
`invention, the first electrode can be a reflection electrode,
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`(14) Further, in (13) according to the invention, the reflec-
`tion electrode can have unevenness therein.
`
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`(15) Further, in any one of (1) to (11) according to the
`
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`
`
`invention, the first electrode can be a transparent electrode
`and a rcflcction clcctrodc.
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`
`(16) Further, any one of (l) to (15) according to the
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`
`
`invention can be adapted such that the first electrode is a
`
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`counter electrode and the liquid crystals are driven by an
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`electric field generated by the first electrode and the second
`electrode.
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`(17) Further, in (16) according to the invention, a slit can be
`formed to the first electrode.
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`[0026]
`Further, any one of (1) to (15) according to the
`
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`
`invention can be adapted such that the second electrode is a
`
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`counter electrode and the liquid crystals are driven by an
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`electric field generated by the counter electrode and the
`second electrode.
`
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`
`in any one of (l) to (18) according to the
`(18) Further,
`
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`
`
`invention, a third insulating film can be disposed between
`the first electrode and the second electrode.
`
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`
`
`(20) Further, in any one of (l) to (19) according to the
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`
`invention, the surface of the second insulating film can be
`
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`
`made planar.
`
`
`[0027]
`(21) Then, a method of fabricating a liquid crystal
`
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`
`
`display device according to the invention includes a process
`of:
`
`
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`
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`
`
`forming an active device on the main surface of the
`[0028]
`
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`
`first substrate,
`
`
`stacking a first insulating film, a first electrode, a
`[0029]
`
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`
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`
`
`second insulating film, and a second electrode in this order
`
`
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`
`in the layer above the active device,
`
`
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`
`
`forming the second insulating film between the first
`[0030]
`electrode and the second electrode and in the inside of the
`
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`first through holc by using a coatablc transparcnt insulating
`
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`
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`film having a specific dielectric constant of 4.0 or higher,
`
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`[0031]
`forming a second through hole to the second insu-
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`lating film in the inside of the first through hole,
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`electrically connecting the second electrode con—
`[0032]
`
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`
`stituting a pixel electrode by way of the second contact hole
`
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`to the active device, and
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`
`forming a storage capacitance by the first electrode,
`[0033]
`
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`in
`the second electrode, and the second insulating film,
`
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`which the second insulating film is made photosensitive, and
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`exposure and development in a predetermined pattern are
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`applied to the second insulating film to fonn the second
`
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`through holes.
`
`
`[0034] The constitutions described in (l) to (21) above are
`
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`
`
`only examples and the invention is not restricted to them.
`
`
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`
`
`[Specific dielectric constant], [material], [fine par-
`[0035]
`
`
`
`
`
`
`
`ticles],
`[grain size],
`[sol—gel],
`[photosensitivity],
`[mixing
`
`
`
`
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`ratio], [film thickness], [transmittance], [refractive index],
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`Page 10 of 22
`
`Page 10 of 22
`
`

`

`US 2008/00188l6 Al
`
`Jan. 24, 2008
`
`more of them may be used in admixture. The specific
`dielectric constant of the polymers is about from 3 to 3.5.
`Further. the polymers can be mixed with a photosensitive
`ingredient for providing the photosensitivity. Further. a
`photosensitive ingredient may be directly attached to the
`polymer.
`
`[Fine Particles]:
`
`In the coatablc transparent insulating film having a
`[0041]
`specific dielectric constant of 4.0 or higher. the fine particles
`having a specific dielectric constant higher than that of the
`transparent film material include metal oxides such as tita-
`nium oxide (TiOz). altuninum oxide (A1203). barium titan-
`ate (BaTiOJ).
`tantalum oxide (Ta205,). zirconium oxide
`(ZrOZ). hafnium oxide (HR)2). niobium oxide (NbZO5 ). and
`yttrium oxide (Y203). Further they also include metal
`nitrides of high specific dielectric constant, for example.
`silicon nitride (Si3N4). Such fine particles may be used each
`alone. or two or more ofthem may be used in admixture. The
`following Table 1 shows dielectric materials and features
`thereof.
`
` TABLE 1
`
`Refract ion
`index
`
`Feature
`
`13-255
`
`lnexpensive.
`high
`transparent
`Extremely
`high
`dielectric
`constant
`Inexpensive.
`high
`transparent
`
`Highly
`transparent
`
`Chemical
`fonnula
`
`'I'rO,
`
`Specific
`dielectric
`constant
`
`X. y - 8.1.
`2 = 173
`
`High
`dielectric
`material
`
`'l'itsmium
`oxide
`
`Barium
`titanste
`
`Aluminturr
`oxide
`
`Tantalum
`oxide
`Zirconium
`oxide
`Hafuium
`oxide
`Yttrium
`oxide
`Niobium
`oxide
`Silicon
`oxide
`
`BaTiOJ
`
`1200—2900
`
`2.3-2.4
`
`A120;
`
`121105
`
`ZrO,
`
`HtDl
`
`YZOS
`
`N150,
`
`Si3N4
`
`1.67
`
`2.16
`
`2.05
`
`1.95
`
`1.87
`
`2.33
`
`8.5-10
`
`25
`
`11-185
`
`24
`
`l I
`
`46
`
`7-8
`
`[Grain Size]:
`
`the
`In a case of adding them as fine particles.
`[0042]
`primary grain size thereof is. preferably. 30 nm or less and.
`more preferably. 20 nm or less. In a case where the grain size
`is larger than that described above. the light scattering effect
`tends to increase and a transparent film is dillieult to obtain.
`On the other hand. even when the primary grain size is
`small. agglomeration may cause scattering. those not caus-
`ing agglomeration are desirable.
`[0043]
`Further. depending on the material. some activity is
`shown sometimes. For example. referring to 'l'i()2.
`it has
`been known that crystals of an anatase type show photo-
`catalytic activity. However. since the activity may lead to the
`deterioration of the material thus giving undesired etfects in
`the application use of the invention. those of a mtile type
`showing less photocatalytic activity are desired. Further. it is
`
`[planarity]. etc. in the typical constitutional examples of the
`invention described above are to be explained.
`
`[Specific Dielectric Constant]:
`
`[0036] The coatable transparent insulating film having the
`specific dielectric constant of 4.0 or higher includes those
`materials containing at least a transparent film constituting
`the main material thereof. fine particles or a sol-gel having
`a specific dielectric constant higher than that of the trans-
`parent
`film material.
`'l'he specific dielectric constant
`is.
`preferably. 4.0 or higher and. preferably. 6.0 or higher. The
`reason is as described below.
`[0037] That is. fineness has made higher also in a medium-
`to-small si7ed liquid crystal displays typically represented
`by the liquid crystal panel of a mobile telephone and it is
`considered that QV( iA (320x240 pixels) at present will shift
`to VGA (640x480 pixel) class in the feature. Considering a
`2.4 inch (nominal) panel of VGA and assuming that a
`storage capacitance of 60 fF is necessary and the electrode
`area thereof is 400 umz. The inter-electrode distance d is
`about 195 nm in a case of using a material having a specific
`dielectric constant of 4.0 or less. for example. a coatablc
`insulating film such as of an acrylate polymer having a
`specific dielectric constant of 3.3 known so far according to
`the relation:
`
`C=E,E(,S/d
`
`(1)
`
`(in which C: capacitance. 6,: specific dielectric constant.
`60: dielectric constant of vacuum. S: electrode area. d: inter
`electrode distance). Accordingly.
`it is necessary to control
`the thickness of the coatablc insulating film to about 200 nm.
`[0038] As shown in the formula (1) above. since the
`capacitance C and the electrode area S are in proportion. the
`capacitance cart be made larger when the electrode area can
`be enlarged. However. decrease of the electrode area is
`limited in view of the trend of making the fineness higher as
`has been described above. Since the inter-electrode distance
`d is in an inverse proportion to the capacitance. it is possible
`to improve the capacitance by decreasing the inter-electrode
`distance ((1). However. the withstand voltage and the leakage
`current provide a problem in this case. Actually.
`in an
`organic film at a film thickness of about 200 nm. it may be
`a high possibility that the withstand voltage and the leak
`current result in the problem.
`[0039]
`()n the contrary.
`in a case of using a material
`having a specific dielectric constant. for example. of 5.0. the
`inter-electrode distance is 300 nm according to the formula
`(1) and this is advantageous in view of the withstand voltage
`and the leakage current by so much as the thickness can be
`increased. In a case where the dielectric constant is further
`higher. the effect is firrther improved.
`
`[Material] (Organic Polymer):
`
`[0040] For the coatablc transparent insulating film having
`a specific dielectric constant of 4.0 or higher used in the
`invention. the transparent film constituting the main portion
`thereof includes polyacrylate derivatives. polymethacrylate
`derivatives. polystyrene derivatives. polyolefin derivatives.
`and copolymers thereof. 'Ihose other than described above
`can also be used so long as they are highly transparent in a
`visible region and not colored by a heat treatment at about
`200° C. For the molecular weight. those having a weight
`average molecular weight of about 1.000 to 100.000 are
`preferred. Such polymers can be used each alone or two or
`
`Page 11 of 22
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`

`

`US 2008/0018816 A1
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`
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`
`
`Jan. 24, 2008
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`
`
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`
`
`sensitivity, it is necessary for coating and curing the coatable
`
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`
`
`transparent insulating film, then coating additionally a pho-
`
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`
`
`tosensitive photoresist or the like to the upper layer, baking,
`
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`
`
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`
`
`exposing and developing the same to form a pattern. Further,
`
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`
`
`since it is necessary to etch the coatable transparent insu-
`
`
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`
`
`lating film in the lower layer using the resist as a mask,
`
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`
`
`transfer the pattern and, finally, remove the photoresist in the
`
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`
`
`upper layer, this makes the step lengthy.
`
`
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`
`
`[0050] On the other hand, in a case where the coatable
`
`
`
`
`
`
`
`
`
`
`
`transparent insulating film having a dielectric specific con-
`
`
`
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`
`
`
`stant of 4.0 or higher has a photosensitivity, since the film
`
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`
`
`per se is sensitive to the light,
`it can be coated, baked,
`
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`
`
`
`exposed and developed to form a pattern and the step is
`
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`
`
`completed by the subsequent photo-bleaching and curing.
`
`
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`
`
`Accordingly, this is advantageous since the pattern can be
`
`
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`
`
`
`
`
`
`formed simply and conveniently.
`
`
`
`
`[0051] For providing the coatable transparent insulating
`
`
`
`
`
`
`
`film with the photosensitivity, the binder for the organic
`
`
`
`
`
`
`
`
`
`polymer described above includes, for example, those con-
`
`
`
`
`
`
`
`taining at least a polymer using an alkali soluble unit such
`
`
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`
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`
`
`
`
`as a carboxylic acid and a diazonaphthoquinone as a pho-
`
`
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`
`
`
`
`tosensitizer. In such material, since diazonaphthoquinone is
`
`
`
`
`
`
`
`decomposed by exposure and transformed into indene car-
`
`
`
`
`
`
`
`boxylic acid to increase the alkali solubility, the exposed
`
`
`
`
`
`
`
`
`portion is removed by alkali development to obtain a posi-
`
`
`
`
`
`
`
`
`
`tive type pattern.
`
`
`
`Further, the binder of the organic polymer can be
`[0052]
`
`
`
`
`
`
`
`
`
`
`incorporated with epoxy units that cause heat crosslinking or
`
`
`
`
`
`
`
`
`
`polymerizable units such as acrylate units on the side chains
`
`
`
`
`
`
`
`
`
`
`for curing the film after forming the pattern by exposure and
`
`
`
`
`
`
`
`
`
`
`
`development.
`
`[0053] Another method of providing the photosensitivity,
`
`
`
`
`
`
`
`an alkali soluble unit such as a carboxylic acid is used as a
`
`
`
`
`
`
`
`
`
`
`
`
`
`binder for the organic polymer described above and a
`
`
`
`
`
`
`
`
`
`polymer having photo-reactive units groups such as acrylate
`
`
`
`
`
`
`
`
`units or methacrylate units on the side chains are used and
`
`
`
`
`
`
`
`
`
`
`
`a photo-initiator and, optionally, a polyftmctional photo-
`
`
`
`
`
`
`reactive oligomer are incorporated. By using such a mate-
`
`
`
`
`
`
`
`
`rial, photopolymerization is initiated by exposure to cause
`
`
`
`
`
`
`
`crosslinking in the exposed portion and a not exposed
`
`
`
`
`
`
`
`
`portion is removed by alkali development to obtain a nega-
`
`
`
`
`
`
`
`
`tive type pattern.
`
`
`
`[Photosensitive Sol-Gel]:
`
`
`[0054]
`In a case of using a sol-gel of a metal oxide as a
`
`
`
`
`
`
`
`
`
`
`
`high-k dielectric material having a specific dielectric con-
`
`
`
`
`
`
`
`stant 5.0 or more, for example, TiOZ, A1203, BaTiO3, TaZOS,
`
`
`
`
`
`
`ZrOZ, ZnO, HfOZ, NbZOS, and Y203, since sol-gel can
`
`
`
`
`
`
`
`
`
`provide by itself a transparent coating film, it can be used as
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`a photosensitive material by incorporation of a photosensi-
`
`
`
`
`
`
`tive ingredient thereto. Specifically, a negative type photo—
`
`
`
`
`
`
`
`sensitive composition in which the exposed portion is ren-
`
`
`
`
`
`
`
`
`dered insoluble can be formed by adding a photo-acid
`
`
`
`
`
`
`
`
`
`generator such as an onium salt, or sulfonic and imide.
`
`
`
`
`
`
`
`
`
`
`Further, a positive type photosensitive composition improv-
`
`
`
`
`
`
`ing the solubility of the exposed portion can also be formed
`
`
`
`
`
`
`
`
`
`
`
`by a diazonaphthoquinone type material.
`
`
`
`
`[Mixing Ratio]:
`
`
`[0055] The ratio of the fine particles or the sol-gel having
`
`
`
`
`
`
`
`
`
`
`a specific dielectric constant higher than that of the trans-
`
`
`
`
`
`
`
`
`
`parent film material relative to the transparent film consti—
`
`
`
`
`
`
`
`
`tuting the main body of the invention can be varied option-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`also preferred that the periphery of the particle is covered
`
`
`
`
`
`
`
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`with a more stable material such as SiO2 or A1203.
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`[0044]
`For avoiding agglomeration of the fine particles,
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`the fine particle of high—k dielectric material used in the
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`invention is preferably treated with a surface treating agent
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`further at the periphery thereof. The fine particles are coated
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`optionally in admixture with a binder or an organic polymer
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`as the photosensitive ingredient in an appropriate solvent.
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`Accordingly, for improving the dispersibility of them in the
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`solution,
`those applied with a surface treatment by an
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`appropriate surface treating agent are preferred. Specific
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`surface treating agent includes, for example, silane coupling
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`reagents, polysilicon derivatives and stearic acid.
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`[Sol—Gel]:
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`[0045] The coatable transparent insulating film having a
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`specific dielectric constant of 4.0 or higher used in the
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`invention may be those containing a sol-gel having a specific
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`dielectric constant higher than that of the transparent film
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`material. The sol-gel includes those of metal oxides sol-gel
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`such as titanium oxide (TiOZ), aluminum oxide (A1203),
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`barium titanate (BaTiO3), tantalum oxide (TaZOS), zirco—
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`nium oxide (ZrOZ), hafnium oxide (HfOZ), niobium oxide
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`(NbZOS), and yttrium oxide (Y203). The sol-gel may be used
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`alone or two or more kinds thereof may be used in admix-
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`ture.
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`[0046]
`In the case of the sol-gel, since this is not a particle
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`it has less effect of scattering a light and has a feature that
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`a transparent film can be obtained easily. However, in a case
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`where a coatable transparent insulating film having a spe-
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`cific dielectric constant of 4.0 or higher is a photosensitive
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`material, the sol-gel tends to give an effect on the developing
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`property of the film. The sol-gel may also be used together
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`with the fine particles shown previously.
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`Further, in the case of the sol-gel, it can sometimes
`[0047]
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`form a coating film by itself. Accordingly, in a case where
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`a coatable transparent
`insulating film having a specific
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`dielectric constant of 4.0 or higher can be formed at a desired
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`film thickness by using the sol-gel alone, the film may be
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`for